I have downloaded the Rotom and Darkrai events to my Platinum, but, besides that, I'm greatly disappointed in how I played. If I restart, will I lose my downloads?
Do you have a legit game?Yes, everything is fine (it does all you asked). I've also done everything from 1-4 (I'm guessing your mean the elite 4 + champion when referring to the weak 5).
In D/P/Pt the mystery gift has the "get from a friend" option.
How can I send an event item?
If you beat the Elite Four (and Champion), it should come back. (Platinum only)